There is not a single screen where you can see everything - which is not THAT bad.
It's getting slighhtly more problematic that often you get inconsistent numbers at different screens.
Anyway, if you concern is "just" balancing your budget - that can be done.
I'd start at the empire Summary Screen.
Here you can get 3 main information:
#1) Colonies of the Empire
"Your world economies turns out a total revenue of $28974 .... our profit is $8993"
#2) Colony Status
"Maintenance costs $12925"
#3) Fleet
"Fleet maintenance costs $7056"
So this gets you the broad picture
Total income: +29000
./. Colonies: - 13000
./. Fleet : - 7000
= Profit: +9000
The good news here is that those numbers add up and give you a good indication where to start looking for budget balancing.
Another good information you can find in this screen is the maintenance rate for colonies and fleet.
Fleet maintenance rate is mainly driven (afaik) where your ships are (green or red fields) and if you got many damaged ships and/or low WF
Colony maintenance is driven by colony morale
Both are also influenced by politics afaik.
If one (or both) of those rates are very high (>100%) - start looking for reasons for that (more about that below).
Now the question you got to raise is if you are in immediate financial trouble or if you still got sufficients funds but are burning through them turn by turn.
If you are in immediate financial stress and need to get a profit right now, there are 3 main options for you:
1) destroy ships you don't urgently need. concentrate on those ships that are badly damaged.
The "Ship" button on the map screen can help you indentify the most costly ships.
For each ship you see there the actual maintenance cost and in brackets the "100%" maintenance cost.
I eg have a a ship that is "$100 ($125)" (this is full HPs, full WF at a green field) and another one that is "$273 ($171)" - the latter one is damaged, at low WF and in a red field.
Once I was in a strong financial stress and running low on funds - I scrapped a full fleet if military transports as those ships where all damaged and in red fields.
2) Get as many Planets to Idle production as possible. Quite obvious one.
3) Optimize colony installations.
If you find yourself having built way too strong overcapacity - you might want to consider scrapping some of it. When you for instance got 10 population on a planet but did built 20 Hab units, you might want to consider scrapping some of those. Unused buildings (Habs, factories, Morale,...) just add maintenance without contributing to your economy
But in general you shouldn't get to such a situation in first place.
If you are looking more to the long term, there are way more options of course. It's just general advice now, as there are way too many possibilities to list em all.
- Politics: very important in ST4X , so try to keep as many positive Treaties going as possible.
- don't "overbuild" too much (see above), Try to keep Hab units, Factories and Morale aligned to your actual population, which just a "little" buffer for future growth (how you define "little" is up to you ;-) )
- Keep ships at green fields if you can.
- Try to maximize your income (duh!)
- Sometimes it might be better to scrap badly damaged ships and build them anew (esp. if they got low repair rates)
- ...
